SravnaTestPrep wrote:

St.John's is the best school in the city because one or more of its students have always got selected to the national math olympiad team in the past ten years.

good question. reminds me of an

e-gmat example with GMATClub members and GMAT test takers who get high scores.

so, the assumption here must be that if a school has its students selected for national math olympiad team, then the school can be considered a good one.

Which of the following is an underlying assumption of the argument above?

A. If a student of a school doesn't get selected to the national math olympiad team, then that school cannot be considered good

this one is way too strong. but wait, there are a lot of other students who do not get selected for the math olympiad team, but they might be very good at history, english literature, etc. this one uses way too strong words, such as "cannot be considered". this doesn't allow for any "possibilities". this one tells for certain that if from a school students are not selected for math olympiad, then the school is not a good one. because of this, A can be eliminated.

B. At least one of the students of the best school in a city is highly talented in math.

well, it might be true, but we need an assumption to support the claim that the school is the best in town. So B is out.

C.Selection to the national math olympiad team is extremely difficult

it might be true, or might not. negate this one. The conclusion still stands even if the negated version of C is added to the argument. C is out.

D. Selection of students of a school to the national math olympiad team can be a good indicator of the quality of that school.

Aha! basically what I mentioned above. looks good.

let's try to negate this one:

selection cannot be a good indicator of the quality of the school. wow, now the conclusion is just simply destroyed. so this is a good candidate for the correct answer. let's check for E.

E.Most of the brightest students do not compete for a place in the national math olympiad team

well, this one is out of scope, and completely irrelevant to the conclusion.

D so far is the best answer.